System and Method for Detecting and Storing File Identity Change Information Within a File System

1. A system, comprising: a storage device configured to provide a storage space for data storage; and a file system configured to map file system content to said storage space for storage and to manage access to said storage device, wherein said file system content comprises a plurality of files and metadata records, wherein each of said metadata records is associated with a corresponding one of said plurality of files; wherein said file system is further configured to: detect an identity-modifying file operation specifying one or more source ones of said plurality of files and a destination one of said plurality of files; in response to detecting said identity-modifying file operation, for existing records of operations previously detected by said file system and responsively stored within metadata records associated with said one or more source files, store at least some of said existing records within a metadata record associated with said destination file; in response to storing an indication of said identity-modifying file operation within said metadata record associated with said destination file, store an indication of said identity-modifying file operation in a history stream; in response to detecting said indication of said identity-modifying file operation within said history stream, store a metadata record of said identity-modifying file operation in a database configured to store a plurality of entries, wherein said database is further configured to respond to a query of said plurality of entries; and examine entries in said database to compare a first valid signature of a second file to one or more unique signatures of a first file to establish that the first file is the ancestor of the second file based on a match between said first valid signature and one of said one or more unique signatures.

2. The system as recited in claim 1 , wherein said identity-modifying file operation corresponds to a file rename operation or a file copy operation.

3. The system as recited in claim 1 , wherein said file system comprises said history stream, and wherein said file system is further configured to: in response to detecting said identity-modifying file operation, store an indication of said identity-modifying file operation within a metadata record associated with said destination file.

4. The system as recited in claim 3 , wherein said file system is further configured to scan said history stream independently of detecting identity-modifying file operations.

5. The system as recited in claim 1 , wherein said metadata records are stored in extensible markup language (XML) format.

6. The system as recited in claim 1 , wherein to generate a given one of said existing records of operations previously detected by said file system and responsively stored within metadata records associated with a given one of said one or more source files, said file system is further configured to store a signature corresponding to said given source file within said given existing record.

7. The system as recited in claim 6 , wherein said signature is computed according to a hash-type function of at least a portion of said given source file.

8. A computer-implemented method, comprising: a file system configured to map file system content to a storage space for data storage provided by a storage device and to manage access to said storage device, wherein said file system content comprises a plurality of files and metadata records, wherein each of said metadata records is associated with a corresponding one of said plurality of files; said file system detecting an identity-modifying file operation specifying one or more source ones of said plurality of files and a destination one of said plurality of files; in response to detecting said identity-modifying file operation, for existing records of operations previously detected by said file system and responsively stored within metadata records associated with said one or more source files, said file system storing at least some of said existing records within a metadata record associated with said destination file; in response to storing an indication of said identity-modifying file operation within said metadata record associated with said destination file, storing an indication of said identity-modifying file operation in a history stream; in response to detecting said indication of said identity-modifying file operation within said history stream, storing a metadata record of said identity-modifying file operation in a database configured to store a plurality of entries, wherein said database is timber configured to respond to a query of said plurality of entries; and examining entries in said database to compare a first valid signature of a second file to one or more unique signatures of a first file to establish that the first file is the ancestor of the second file based on a match between said first valid signature and one of said one or more unique signatures.

9. The method as recited in claim 8 , wherein said identity-modifying file operation corresponds to a file rename operation or a file copy operation.

10. The method as recited in claim 8 , wherein said file system comprises said history stream, and wherein the method further comprises: in response to detecting said identity-modifying file operation, said file system storing an indication of said identity-modifying file operation within a metadata record associated with said destination file.

11. The method as recited in claim 10 , further comprising: said file system scanning said history stream independently of detecting identity-modifying file operations.

12. The method as recited in claim 8 , wherein said metadata records are stored in extensible markup language (XML) format.

13. The method as recited in claim 8 , wherein said file system generating a given one of said existing records of operations previously detected by said file system and responsively stored within metadata records associated with a given one of said one or more source files comprises said file system storing a signature corresponding to said given source file within said given existing record.

14. The method as recited in claim 13 , further comprising said file system computing said signature is computed according to a hash-type function of at least a portion of said given source file.

15. A computer-accessible storage medium storing program instructions, wherein the program instructions are computer-executable to implement: a file system configured to map file system content to a storage space for data storage provided by a storage device and to manage access to said storage device, wherein said file system content comprises a plurality of files and metadata records, wherein each of said metadata records is associated with a corresponding one of said plurality of files; said file system detecting an identity-modifying file operation specifying one or more source ones of said plurality of files and a destination one of said plurality of files; in response to detecting said identity-modifying file operation, for existing records of operations previously detected by said file system and responsively stored within metadata records associated with said one or more source files, said file system storing at least some of said existing records within a metadata record associated with said destination file; in response to storing an indication of said identity-modifying file operation within a metadata record associated with said destination file, storing an indication of said identity-modifying file operation in a history stream; in response to detecting said indication of said identity-modifying file operation within said history stream, storing a metadata record of said identity-modifying file operation in a database configured to store a plurality of entries, wherein said database is further configured to respond to a query of said plurality of entries; and examining entries in said database to compare a first valid signature of a second file to one or more unique signatures of a first file to establish that the first file is the ancestor of the second file based on a match between said first valid signature and one of said one or more unique signatures.

16. The computer-accessible storage medium as recited in claim 15 , wherein said identity-modifying file operation corresponds to a file rename operation or a file copy operation.

17. The computer-accessible storage medium as recited in claim 15 , wherein said file system comprises said history stream, and wherein the program instructions are further computer-executable to implement: in response to detecting said identity-modifying file operation, said file system storing an indication of said identity-modifying file operation within a metadata record associated with said destination file.

18. The computer-accessible storage medium as recited in claim 17 , wherein the program instructions are farther computer-executable to implement: said file system scanning said history stream independently of detecting identity-modifying file operations.

19. The computer-accessible storage medium as recited in claim 15 , wherein said metadata records are stored in extensible markup language (XML) format.

20. The computer-accessible storage medium as recited in claim 15 , wherein said file system generating a given one of said existing records of operations previously detected by said file system and responsively stored within metadata records associated with a given one of said one or more source files comprises said file system storing a signature corresponding to said given source file within said given existing record.

21. The computer-accessible storage medium as recited in claim 20 , wherein the program instructions are further computer-executable to implement said file system computing said signature according to a hash-type function of at least a portion of said given source file.